DEVMO Mini Handy 2~150mA LED Tester Test Box for Light-Emitting Diode Bulb Lamp

hi there welcome once again in this video tutorial we will learn how to check led bulbs with the help of a digital multimeter so let's begin as you can see guys it's a led bulb and it's work on three volt dc it has two legs one is long and second is short the long leg is called anode and the short leg is called cathode and now let's check leds take a digital multimeter and rotate the switch onto continuity range or beep range take a led and touch the red probe of the multimeter to the anode and black prop to the cathode point of the led bulb and now as you can see led is glowing guys let me clear one thing when we give positive supply to the anode and negative supply to the cathode it is called forward biasing take the one more led and as you can see guys this led is not working and not emitting any lights it's a useless or bad led and now let's check another led so touch the red probe